Generate TAGS for all the project dependencies with codex update command and then load them with M-x visit-tags-table. Jump to tag is now possible with M-..
Color Themes
When switching between them, disable previous themes with M-x disable-theme to not have interference.
Tags
Create tags with custom script ctags-citre.
Tags are not used if eglot is enabled. Disable it with eglot-shutdown to use tags with citre.
List annotations with annotate-show-annotation-summary
Disable with annotate-toggle-all-annotations-text
Overlay a symbol with symbol-overlay-put
Disable with symbol-overlay-remove-all
Merging changes
vdiff / ediff: to merge changes between different files
smerge-mode / smerge-ediff: to merge diff3 output from git
Spelling
Correct closest misspelled word with z =.
Change language with jinx-languages.
Enable text-mode to check the grammar with languagetool (run first systemctl start languagetool.service).
Tree-Sitter
Highlight nodes of the code with tree-sitter-query-builder. You can see the full code structure with tree-sitter-debug-mode. Highlight query example for Python: